發(fā)布時間：2018-07-08 13:46

  本文選題：過渡金屬氮化物 + 催化劑載體��； 參考：《廣東工業(yè)大學(xué)》2015年碩士論文

【摘要】：低溫燃料電池中,鉑碳催化劑由于碳載體與負(fù)載的鉑粒子結(jié)合不牢固,催化過程中兩者無協(xié)同作用,且碳載體易被腐蝕,造成鉑顆粒的遷移、脫落和團(tuán)聚,嚴(yán)重縮短了燃料電池的使用壽命,所以開發(fā)具有高活性和高穩(wěn)定性的新型鉑基催化劑及研究其協(xié)同催化機(jī)理具有十分重要的意義。本文使用溶劑熱/水熱法-后氮化處理方法可控合成了三種過渡金屬氮化物：氮化鈦納米管(TiN NTs)、氮化鉬鈦(Ti0.8Mo0.2N)和氮化鈷鈦(Ti0.9Co0.1 N)納米顆粒,并將其作為鉑基催化劑載體。通過X射線衍射(XRD)、掃描電鏡(SEM)、透射電鏡(TEM)、比表面積測試(BET)、X射線光電子能譜(XPS)和電化學(xué)方法對合成的催化劑的結(jié)構(gòu)表征、電催化性能進(jìn)行了研究。Pt/TiN NTs催化劑的氧還原性能測試結(jié)果表明,其具有高催化活性及穩(wěn)定性。加速老化測試結(jié)果表明氮化鈦納米管載體可以提高催化劑的耐久性能,減少鉑的電化學(xué)活性比表面積的損失。12000圈加速老化測試后,Pt/TiN NTs催化劑的電化學(xué)活性比表面積依然保持在77%,明顯優(yōu)于Pt/C (JM)催化劑。由于氮化鈦納米管粗糙的表面結(jié)構(gòu),可以重新捕獲催化反應(yīng)過程中溶解的鉑顆粒,減少了鉑的脫落及遷移,實驗結(jié)果也證實了鉑顆粒與氮化鈦納米管載體間有強(qiáng)相互作用。Pt/Ti0.8Mo0.2N催化劑的XRD和TEM測試結(jié)果說明了氮化鉬鈦是由單相晶體組成的,并且在甲醇氧化電催化測試中,氮化鉬鈦作為Pt催化劑載體對比Pt/C(JM)催化劑具有更高的質(zhì)量比活性及耐久性。實驗結(jié)果表明鉬的摻雜是產(chǎn)生協(xié)同催化及電子效應(yīng)的原因。Pt/Ti0.9Co0.1N催化劑在氧還原性能測試中表現(xiàn)出高催化活性和穩(wěn)定性的特點。XRD和TEM測試結(jié)果表明氮化鈷鈦納米顆粒是由高純單相晶體組成。通過XPS測試可以看出鉑顆粒與氮化鈷鈦載體間具有強(qiáng)相互作用。氧還原性能測試結(jié)果表明,對比Pt/C(JM)催化劑,Pt/Ti0.9Co0.1N催化劑具有更高的質(zhì)量比活性和耐久性。經(jīng)過10000圈的加速老化測試,Pt/Ti0.9Co0.1N催化劑依舊存在60%的電化學(xué)活性比表面積,遠(yuǎn)遠(yuǎn)高出Pt/C(JM)催化劑。實驗結(jié)果表明,由于鈷的摻雜,改變了鉑的電子結(jié)構(gòu),使得鉑顆粒與載體間的相互作用得到加強(qiáng)。
[Abstract]:In low temperature fuel cells, platinum / carbon catalyst has no synergistic effect due to the weak binding between carbon carrier and supported platinum particles, and the carbon carrier is easy to be corroded, resulting in the migration, falling off and agglomeration of platinum particles. Therefore, it is of great significance to develop a new platinum-based catalyst with high activity and stability and to study its synergistic mechanism. Three kinds of transition metal nitrides, titanium nitride nanotubes (tin NTs), molybdenum titanium nitride (Ti 0.8Mo 0.2N) and cobalt titanium nitride (Ti 0.9Co 0.1 N) nanoparticles were synthesized by solvothermal / hydrothermal method and post-nitridation treatment. The catalysts were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), specific surface area measurement (BET), X-ray photoelectron spectroscopy (XPS) and electrochemical methods. The oxygen reduction performance of the catalyst. PT / tin NTs was studied. The results showed that the catalyst had high catalytic activity and stability. The results of accelerated aging test showed that the support of titanium nitride nanotubes could improve the durability of the catalyst. After accelerated aging test, the electrochemical activity specific surface area of Pt / tin NTs catalyst remained at 77%, which was obviously superior to that of PT / C (JM) catalyst. Due to the rough surface structure of titanium nitride nanotubes, platinum particles dissolved in the catalytic reaction can be recaptured, thus reducing the falling off and migration of platinum. The results also confirmed the strong interaction between platinum particles and titanium nitride nanotube support. The XRD and TEM results of Pt / Ti _ 0.8Mo _ (0.2N) catalyst showed that Mo-Ti nitride was composed of single phase crystal and was used in methanol oxidation electrocatalysis test. Compared with PT / C (JM) catalyst, Mo Ti nitride as Pt catalyst carrier has higher mass specific activity and durability than Pt- C (JM) catalyst. The results show that the doping of molybdenum is the cause of co-catalysis and electron effect. The catalytic activity and stability of Pt / Ti _ 0.9Co _ (0.1N) catalyst showed high catalytic activity and stability in oxygen reduction test. XRD and TEM results showed that cobalt and titanium nitride nanoparticles showed high catalytic activity and stability. Is composed of high-purity single-phase crystals. XPS results show that there is a strong interaction between platinum particles and cobalt-titanium nitride carriers. The results of oxygen reduction test showed that compared with Pt / Ti _ 0.9Co _ (0.1N) catalyst, Pt- / Ti _ (0.9) Co _ (0.1N) catalyst had higher mass specific activity and durability than that of PT / C (JM) catalyst. After 10000 cycles of accelerated aging test, the electrochemical activity specific surface area of PTR / Ti0.9Co0.1N catalyst is still 60%, which is much higher than that of PTR / C (JM) catalyst. The experimental results show that the electronic structure of platinum is changed due to cobalt doping and the interaction between platinum particles and support is strengthened.
【學(xué)位授予單位】：廣東工業(yè)大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2015
【分類號】：TM911.46;O643.36

【參考文獻(xiàn)】

相關(guān)博士學(xué)位論文 前1條

1 岳瑞瑞;導(dǎo)電高分子負(fù)載貴金屬復(fù)合催化劑的制備及電催化性能研究[D];蘇州大學(xué);2014年

，

本文編號：2107629